1. Field of the Invention
The present invention relates to a novel recording medium employing a plurality of photosensitive proteins each having a different photosensitive wavelength, and also to a process for forming a color image with use of this recording medium.
2. Related Background Art
Most general processes for forming a color image are known to include a silver salt color photographic process in which a silver halide (a silver salt), a sensitizing dye, a photocoupler dye and so forth are combined. This process can afford to obtain an image with high sensitivity, high resolution and high precision, but has a certain limit for achieving a low cost because exposure, developing and fixing processes are complicated or there is used expensive silver.
On the other hand, an electrophotographic process according to the so-called electrostatic recording has advantages such that it is simple in the process itself as compared with the silver salt color photographic process, and requires only a low running cost, but has also disadvantages such that the process can produce a color image only with difficulty, cannot readily give a highly precise image, or cannot present a halftone with ease.
In contrast to these processes, D. F. O'Brien U.S. Pat. Nos. 4,084,967 and 4,356,256 disclose an image formation process utilizing rhodopsin, as an image formation process utilizing a reaction in a living body.
The above D. F. O'Brien's image formation process utilizes the function of rhodopsin that is a substance present in the retina of a living body and capable of participating in the photosensing with a remarkably high sensitivity and resolution in the living body, and is effective for attaining a high amplification factor, high sensitivity or high resolution. However, this process can only be applied in the formation of a single color image, and there is no disclosure as to the formation of a full color image.
The present inventors have made intensive studies with an aim to utilize photosensitive proteins, including rhodopsin, for the formation of a full color image while making the most of the properties inherent therein, thus having accomplished the present invention.